(function (doc, win) {
    var docEl = doc.documentElement,
        resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
        recalc = function () {
            if (docEl.clientWidth > 750) {
                docEl.style.fontSize = '100px'
            } else {
                var width = docEl.clientWidth / 7.5;
                docEl.style.fontSize = width + 'px'
            }
        };
    if(!doc.addEventListener) return;
    window.addEventListener(resizeEvt, recalc, false);
    doc.addEventListener('DOMContentLoaded', recalc, false);
})(document, window)